Write Note on lambda phage vectors? Also give its advantages over plasmid vector.
Answers
Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli (E. coli). It was discovered by Esther Lederberg in 1950 when she noticed that streaks of mixtures of two E. coli strains, one of which treated with ultraviolet light, was "nibbled and plaqued". The wild type of this virus has a temperate lifecycle that allows it to either reside within the genome of its host through lysogeny or enter into a lytic phase (during which it kills and lyses the cell to produce offspring); mutant strains are unable to lysogenize cells – instead, they grow and enter the lytic cycle after superinfecting an already lysogenized cell.
Plasmids are extrachromosomal double-stranded circular DNA molecules that can be found in various bacteria and some eukaryotes. Plasmids often contain genes encoding enzymes that confer a certain selective advantage to the host cell. Such selective advantages include resistance to certain antibiotics.